n=27
%n=20
%del=0.25
del=0.1
t=[0:del:n]
u=[ones(1,length(t))]
x=exp(-2*t)
y=conv(u,x)
ny=[0:del:2*n]
subplot(3,1,1)
bar(t,x)
subplot(3,1,2)
bar(t,u)
subplot(3,1,3)
bar(ny,y)
